Recent Advances in Combretastatin A-4 Inspired Inhibitors of Tubulin Polymerization-An Update

Cancer is one of the leading causes of fatality and mortality worldwide. Investigations on developing therapeutic strategies for cancer are supported throughout the world. The massive achievements in molecular sciences involving biochemistry, molecular chemistry, medicine, and pharmacy, and high throughput techniques such as genomics and proteomics have helped to create new potential drug targets for cancer treatment. Microtubules are very attractive targets for cancer therapy because of the crucial roles they play in cell division. In recent years, lots of efforts have been put into the identification of new microtubule-targeting agents (MTAs) in anticancer therapy. Combretastatin A-4 (CA-4) is a natural compound that binds to microtubules’ colchicine binding site and inhibits microtubule polymerization. Due to CA-4’s structural simplicity, many analogs have been synthesized. This article summarizes the new molecule development efforts to reach CA-4 analogs by modifications on its pharmacophore groups, published since 2015.

Simple representation of the quantum entanglement of coupled harmonic oscillators in terms of the reflection coefficient

Quantum entanglement of coupled harmonic oscillators is frequently applied in quantum and non-linear physics, molecular chemistry and biophysics, which is why its study is of a great interest for modern physics. In this work a quantum entanglement of a coupled harmonic oscillator in a simple form was found. This simple form is presented as a single parameter – reflection coefficient R. All parameters of the studied system are included in the R coefficient. It is shown that the derivation of the expression can have applications in quantum optics, in particular in quantum metrology.

70 Years Ferrocene!

Some of the most important features of ferrocene chemistry – structure, reactivity, redox properties, and applications – are presented. Their value in the context of conveying many fundamental aspects of molecular chemistry is considered.

Hyper-Wiener index for fuzzy graph and its application in share market

Topological indices have an important role in molecular chemistry, network theory, spectral graph theory and several physical worlds. Most of the topological indices are defined in a crisp graph. As fuzzy graphs are more generalization of crisp graphs, those indices have more application in fuzzy graphs also. In this article, we introduced the fuzzy hyper-Wiener index (FHWI) and studied this index for various fuzzy graphs like path, cycle, star, etc and provided some interesting bounds of FHWI for that fuzzy graph. A lower bound of FHWI is established for n-vertex connected fuzzy graph depending on strength of a strong edges. A relation between FHWI of a tree and its maximum spanning tree is established and this index is calculated for the saturated cycle. Also, at the end of the article, an application in the share market of this index is presented.

Acceleration of lipid reproduction by emergence of microscopic motion

Self-reproducing molecules abound in nature where they support growth and motion of living systems. In artificial settings, chemical reactions can also show complex kinetics of reproduction, however integrating self-reproducing molecules into larger chemical systems remains a challenge towards achieving higher order functionality. Here, we show that self-reproducing lipids can initiate, sustain and accelerate the movement of octanol droplets in water. Reciprocally, the chemotactic movement of the octanol droplets increases the rate of lipid reproduction substantially. Reciprocal coupling between bond-forming chemistry and droplet motility is thus established as an effect of the interplay between molecular-scale events (the self-reproduction of lipid molecules) and microscopic events (the chemotactic movement of the droplets). This coupling between molecular chemistry and microscopic motility offers alternative means of performing work and catalysis in micro-heterogeneous environments.

First Zagreb index on a fuzzy graph and its application

The Zagreb index (ZI) is a very important graph parameter and it is extensively used in molecular chemistry, spectral graph theory, network theory and several fields of mathematics and chemistry. In this article, the first ZI is studied for several fuzzy graphs like path, cycle, star, fuzzy subgraph, etc. and presented an ample number of results. Also, it is established that the complete fuzzy graph has maximal first ZI among n-vertex fuzzy graphs. Some bounds of first ZI are discussed for Cartesian product, composition, union and join of two fuzzy graphs. An algorithm has been designed to calculate the first ZI of a fuzzy graph. At the end of the article, a multi-criteria decision making (MCDM) method is provided using the first ZI of a fuzzy graph to find the best employee in a company. Also a comparison is provided among related indices on the result of application and shown that our method gives better results.

Collisional (de-)excitation of protonated cyanoacetylene (HC3NH+) by helium at low and moderate temperatures

ABSTRACT Protonated cyanoacetylene, HC3NH+, is detected in astrophysical media, where it plays a key role as an intermediate in the chemistries of HCN/HNC and of cyanopolyynes. We first generated a potential energy surface (PES) describing the intermonomer interaction between HC3NH+ and He in Jacobi coordinates using the highly correlated CCSD(T)-F12/aug-cc-pVTZ ab initio methodology. Then, scattering calculations based on an exact close-coupling quantum-scattering technique were done to obtain pure rotational cross-sections for the rotational (de-)excitation of HC3NH+ after collision with He for total energies up to 2500 cm−1. These cross-sections are used to deduce the collision rates in the 5–350 K temperature range for the low-lying rotational levels of HC3NH+ (up to $j\,\, = \,\,15$). In addition, we generated an average PES for the HC3NH+–H2 system. The preliminary results show that the H2($j_{\mathrm{H_2}} = 0$) and He state-to-state de-excitation cross-sections have similar magnitudes, even though the H2 cross-sections are larger by a factor of 2–2.5. This work should help with the accurate derivation of protonated cyanoacetylene abundances in non-local thermodynamical equilibrium astrophysical media. These will put more constraints on the chemical pathways involving the formation and destruction of HC3NH+ while going back to the cyanopolyyne family and more generally those parts of nitrogen-containing molecular chemistry.

Digital Oil Model Development and Verification

Advances in digital technologies have the potential to enhance model predictive capability and redefine its boundaries at various scale. Digital oil with accurate representation of atomistic components is a powerful tool to analyze both macroscopic properties and microscopic phenomena of crude oil under any thermodynamic conditions. Digital oil model presented in this paper is the key input in molecular chemistry modeling for designing chemical enhanced oil recovery formulation. Hence, it is constructed based on a fit-for purpose strategy focusing in oil components that have large contribution to microemulsion stability. Complete crude oil composition could comprise over 100,000 components. Lengthy simulation time is required to simulate all crude oil components which is impratical, despite the challenges to identify all crude oil components experimentally. Therefore, we established a practical experimental strategy to identify key crude oil components and constructed the digital oil model based on surrogate components. The surrogate components are representative molecules of the volatiles, saturates, aromatics and resins. Two-dimensional digital oil model, with aromaticity on one axis, and the size of the molecules on the other axis was constructed. We developed algorithm to integrate nuclear magnetic resonance response with architecture of the molecular structure. A group contribution method was implemented to ensure reliable representation of the molecular structure. We constructed the digital oil models for a field in Malaysia Basin. We validated the physical properties of the digital oil model with properties measured from experiment, predicted from molecular dynamics simulation and calculated from quantitative property-property relationship method. Good agreement was obtained from the validation, with less than 5% and 13% variance in crude density and Equivalent Alkane Carbon Number respectively, indicating that the molecular characteristic of the digital oil model was captured correctly. We adopted the digital oil model in molecular chemistry modeling to gain insights into microemulsion formation in chemical enhanced oil recovery formulation design. Digital oil is a robust tool to make predictions when information cannot be extracted from experimental data alone. It can be extended for engineering applications involving processing, safety, hazard, and environmental considerations.